Yesterday, I solved a recurring false alarm caused by a swinging ceiling fan.

Turns out, the fan's shadow was tripping the infrared sensor.

3 comments

3 Comments

harperc791mo agoMost Upvoted

Last year, I fixed a false alarm where the fan's vibration was the real issue. PIR sensors are made to detect heat, so a shadow shouldn't set them off on its own. The problem could be from the fan moving air around, not just the shadow.

jesse_white1929d ago

Read that shadows can trick PIR sensors by changing local heat.

the_lucas1mo ago

My friend had a similar issue. His motion sensor kept getting set off by a shadow from a spinning ceiling fan.